From: "Christopher Hoover" <[EMAIL PROTECTED]> Subject: [time-nuts] 58517A external SMC power versus PORT1 power (was Re: HP Z3801A on eBay -- And check this out as) Date: Sat, 20 Jan 2007 15:47:44 -0800 Message-ID: <[EMAIL PROTECTED]>
> > > Well, I failed to have my Z3801A drive my 58517A over port 1. > > Appling 5V on the SMC connector on the 58517A solved the > > problem. The same Z3801A was feeding the active antenna with > > no problem just a few minutes before, so it is not an issue on > > the Z3801A. > > I've got/had both varieties, and some time ago I mapped out the circuits. > > To be clear (for non-smart spliiters): > > If it has the SMC jack, external DC power must be supplied via the SMC jack. As I suspected. > All of the output ports will sink some current to make receivers happy, but > they will not power the amplifier. Good. > If it doesn't have the SMC jack, power must be supplied via PORT 1. All of > the other ports will sink current to make receivers happy, but they will not > power the amplifier. > > It is easy to convert the external DC version to work with DC on PORT 1. It > just takes a (1206, IIRC) shunt -- the pads are right there near PORT1. It > is a good idea at the same time to pull the current limiting resistor in > series with SMC jack so as to disable that input. Another approach would be to insert diodes such that either the SMC or Port 1 may be used. Cheers, Magnus _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
